Whiteland Village
Mary Longenecker
Structural Option
Senior Thesis
August 7, 2007

Whiteland Village
Outline
• Introduction
• Criteria for Redesign
• Lateral Redesign
– Staggered Truss
– Partially Restrained
Composite Connections
• Construction Management
Issues
• Existing Envelope
Analysis
• Conclusions

Whiteland Village

Retirement Community
Exton, Pennsylvania
1,320,000 sq. ft.
$100-150 million
Design-Build
Dates of Construction
Nov. 2006 - Nov. 2008
Architects:
Dever Architects (Residences)
HLM Design (Commons)
Structural Engineers:
Baker, Ingram & Associates
Construction Managers:
Paul Risk Associates, Inc.
HVAC:
Madsen, Inc.
Electrical:
Meadow Valley Electric
Whiteland Village

Existing Systems
• HVAC
– Central Exhaust System using Energy Wheel
– Chilled Water Cooling
– Gas Hot Water Heating
• Fire Protection
– Wet Sprinkler System
• Electrical
– 208Y/120V from (1) 5kV Transformer
– Onsite Co-generation Plant
Whiteland Village

Existing Structural System
Whiteland Village
• Lateral System
– 10” CMU Shearwalls
– 10” Thick Concrete Shearwalls

Existing Structural System
• Floor System
– 8” Untopped Hollow
Core Precast Plank
– Spanning 30 ft.
– Can be considered a rigid diaphragm
Whiteland Village

Alternate Design Considerations
• Ease of future renovations
• Maximum 1’-8” structural depth
• Constructability
• Cost
• Floor vibration
• Fire protection
Whiteland Village

Staggered Truss
• Full story trusses
– Span transverse width
– Alternate floors
• Advantageous in long and narrow buildings
Whiteland Village

Staggered Truss Alternate
Whiteland Village

Staggered Truss Alternate
Whiteland Village
Truss T1

Staggered Truss Alternate
Whiteland Village
Truss T2

Staggered Truss Alternate
• Floor System
– 8” Untopped Hollow-Core Precast Plank
• Design Base Shear = 462 k
– R = 3 for overall system
– T = Cu * Ta
Whiteland Village

Staggered Truss Alternate
Axial Force in Truss due to Gravity Loads (k)
Whiteland Village

Staggered Truss Alternate
Axial Force in Truss due to Lateral Loads (k)
Whiteland Village

Staggered Truss Alternate
Columns:
W10x100 A992
Diagonals and Verticals:
HSS 8x6x5/8 A500 GrB
Chords:
W10x77 to W10x112 A992
Truss T1
Whiteland Village

Staggered Truss Alternate
Slotted HSS to Gusset
Plate Connection
Details:
Weld Length: 20”
Width: 3/8”
Plate Thickness: 1/2”
Whiteland Village

Staggered Truss Alternate
Foundations
Truss Columns
7’x7’x1’-10” spread footing with (6) #7 bars ea. way
Gravity Columns
4’x4’x1’ spread footing with (4) #5 bars ea. way
Typical Detail of Column Footing
Whiteland Village

Partially Restrained Composite
Connections
• Type 3 connections
– Used with steel frame and composite floor
• Reinforcing in the slab used to create top portion of moment connection
• Shear resistance from seat angle at bottom of connection
Whiteland Village

Partially Restrained Composite
Connections
Whiteland Village
Typical Detail of PRCC

Partially Restrained Composite
Connection Alternate
Whiteland Village

Partially Restrained Composite
Connection Alternate
Whiteland Village
Braced Frame in NS Direction

Partially Restrained Composite
Connection Alternate
Whiteland Village
Braced Frame in EW Direction

Partially Restrained Composite
Connection Alternate
• Floor System Determination
– Using Floor Vibration Serviceability
• 1 1/2” Composite Deck with 5.5” Total
Slab Thickness
• Design Lateral Load = 431 k
– R = 3
– T = Cu * Ta
Whiteland Village

Partially Restrained Composite
Connection Alternate
Frame
NS
EW
Beam Location Connection Beam and Studs Mu (ftk) I
LB
(in^4)
Typ Bay Floor PIN-PIN
Int. Bay Floor PIN-PIN
Ext. Bay Floor PIN-PIN
W21x44 (14)
W16x40 (16)
W16x40 (16)
397
277
277
1420
886
886
• Analysis determined PRCC type connections not warranted in braced frame layout
• Structural depth greater than 1’-8” limit
• Condominium layouts would require changes to allow for bracing
Whiteland Village

Construction Management Issues
• Existing Lateral
System Cost:
$363,000
• Staggered Truss
System Cost:
$610,000
• Existing system more labor-intensive
Whiteland Village
Material
CMU Walls
Conc Walls
Scaffold
Conc Ftgs
Total
Adjusted Total
Total Cost
106236
63120
60255
43285
272896
362618
Existing Lateral System Cost
Material
STL Cols
Fireproofing
HSS Bracing
STL Beams
Conc Ftgs
Total Cost
Adjusted Total
Total Cost
36786
40582
96941
279590
5356
459255
610246
Staggered Truss System Cost

Existing Envelope Analysis
Concerns:
• Drainage
• Drip edge
• Moisture Penetration
Whiteland Village

Existing Envelope Analysis
Roof wells for mechanical units
Whiteland Village

Existing Envelope Analysis
Whiteland Village

Existing Envelope Analysis
• Recommendations
– Add drainage cavity
– Extend drip edge
– Keep existing detailing for mechanical wells
– Onsite checks to ensure detailing complete
Whiteland Village

Conclusions
• Staggered truss is a feasible structural alternate
– Allows for ease of renovation
– More costly system
• Partially restrained composite connections are not feasible
• Envelope details should be reworked to prevent bulk water penetration
Whiteland Village

Acknowledgements
Thanks to the following individuals for their assistance throughout my project:
– Dr. Andres LePage
– Andreas Phelps
– The entire AE Department Faculty and Staff
– Larry Baker and the entire staff of Baker, Ingram & Associates
– John Beers of Paul Risk Associates Inc.
– Partners of Whiteland Village
Special thanks to my friends and family
Whiteland Village

Whiteland Village
Questions